Bearings for supporting main shafts of turbo-machines, such as a gas turbine and a turbocharger, are required to endure severe environments involving high temperature and high speed rotation. Attention has been focused on a foil bearing as a bearing suited to use under such conditions. The foil bearing has bearing surfaces formed of flexible thin films (foils) having low flexural rigidity, and is configured to support a load by allowing the bearing surfaces to be deflected. During the rotation of the shaft, fluid films (such as air films) are formed between an outer peripheral surface of the shaft and the bearing surfaces of the foils, and the shaft is supported in a non-contact manner.
For example, in Patent Literature 1 and Patent Literature 2, there are disclosed turbo-machines to which the foil bearings are applied.
In those turbo-machines, a rotary member is fixed to a turbine shaft, and those components are supported in a freely rotatable manner by foil bearings. The rotary member includes a flange portion projecting radially outward, and the flange portion is supported in thrust directions by the foil bearings.